The heel stick procedure to puncture a newborn's heel to obtain a blood sample is widely practiced for babies aged 6 months and below. The blood samples obtained from this procedure are sent for diagnostic processing predominantly for screening of diseases, for example hypothyroidism, PKV (or phenylketonuria), galactosemia, sickle cell disease, HIV infection, etc. The advantages observed from the screening of these diseases are widely known and will not be discussed.
As the blood samples are to be obtained from infants, any incision should be made with minimum discomfort to the infant and therefore, issues like consistency in the type of incision or puncture, having a minimal depth of cut whilst still being able to obtain an adequate volume of blood for sampling to be performed, are critical. On the other hand, the device has to have ease of use and have repeatability of results.
For hygiene purposes, these devices are made for single usage and therefore, low cost of manufacturing is also a consideration so that a cheap and reliable device may be produced.
For the purposes of safety, the blades of the devices are usually stowed away to prevent cross contamination during disposal.
There are presently several lancet devices available in the market.
Some of these lancet devices produce an incision by way of a substantially downward thrust on a patient causing a puncture wound or a substantially vertical incision, others cause an incision profile by way of a slicing action causing a substantially lateral incision profile.
In the lancet devices of the prior art, the incision is activated by a trigger mechanism, which impacts a blade or blade-carrying portion to cause the incision to occur.
The problem with this type of activation is that the incision is activated indirectly. Possible problems caused by this indirect activation mechanism would be the possibility of the trigger mechanism being jammed or broken and the inconsistency of the impact force resulting in an inconsistent incision.
It is an object of the present invention to alleviate one or all of the above problems.